PoseBone local rotation values to global with axis changed
Not sure what you need. Try this for rotation between local space and world space
for pbone in context.object.pose.bones:
    # This is the transform from bone local space to world space
    world = context.object.matrix_world @ pbone.matrix

    # If there are non-uniform scalings or shears in `world`, this won't work...
    _loc, rot, _scale = world.decompose()
    
    print(rot.to_axis_angle())

If you want the relative rotation from the rest pose to the current pose in world space, maybe this
for pbone in context.object.pose.bones:
    world = context.object.matrix_world @ pbone.matrix
    world_rest = context.object.matrix_world @ pbone.bone.matrix_local

    _loc, rot, _scale = world.decompose()
    _loc, rot_rest, _scale = world_rest.decompose()
    
    print(rot.rotation_difference(rot_rest).to_axis_angle())